Fine solids handling device



Dec. 24, 1963 L. E. MYLTING FINE SOLIDS HANDLING DEVICE Filed Jan. 5, 1961 1N VEN TOR.

United States Patent O 3,115,278 FINE SOLIDS HANDLEJG DEVICE Lauritz E. Mylting, Ardmore, Pa., assignor to AS=H Industries, Inc. Filed dan. 5, 1961, Ser. No. 80,824 6 Claims. (Cl. 222-56) 'Ihis invention relates generally to the pneumatic handling of free owing solids and is more particularly concerned with means for controlling the flow of air and dust in an intermittently feeding, single chamber air lock in a pneumatic materials handling system operating at pressure above atmospheric pressure.

The present invention aims to provide a device 'which will remove such solids rom a hopper by entraining them in an air stream and thereby transporting them to a place of disposal and which will automatically act as an aspirator to exhaust air from the hopper and place it under negative pressure while ymaintaining uninterrupted flow of air through a housing below the hopper. The creation of the negative pressure would prevent dust from blowing out of the hopper and would cause air to flow into the hopper when the gate at the charging opening in the upper part of the hopper is open and solids are being brought into the hopper. The continuous ow of air through the housing would avoid the use of complicated and unsatisfactory means for stopping the ow of air `during the charging of solids into the hopper.

This aim is achieved by means embodying the invention, a preferred form of which is described hereinafter and disclosed in the drawings accompanying and forming a part of this specication in which:

FIGURE 1 is a side view partly in elevation showing the parts of the preferred device `in the ,positions they occupy when solids are being removed from the hopper; and

FIGURE 2 is a fragmentary view similar to part of FIGURE 1 but showing the parts in the position they occupy during the time solids are being charged into the hopper; and

FG. 3 is a sectional, diagrammatic view of a four-way valve for controlling the ilow of air through the housing of FIGS. 1 `and 2.

In the drawings, the hopper 1 may be of any conventional form suitable for receiving nely divided solids. Such solids may be carried in pipe 2 and charged through and into the upper part or hopper `1. A flexible section 2a of pipe connects pipe 2 to hopper 1. `A gate, indicated generally at 3, is provided for controlling the flow of solids through pipe 2 and may be actuated to open and closed position by any suitable means, such as cylinder 4, rod 5 and a piston (not shown) disposed within cylinder 4.

ln its lower portion hopper 1 is provided with an outlet 1u through which solids may ow from the interior of the hopper. A housing 15 is attached to the hopper t1 and defines a chamber 16 below and surrounding outlet 1t) and into which solids `may be discharged through outlet 1G.

Means is provided for feeding -solids through outlet in the chamber 16. While any conventional means may be employed for this purpose, vibrating means is illustrated in FlGURES 1 and 2 and `comprises a substantially horizontal plate 17 disposed beneath the lower end of outlet 101 and a vibrator 18 which supports `and reciprocates the plate 17 rapidly with resultant llow of solids 4off the edges thereof and into the space in chamber V below Ithe plate. It 4will be understood that the plate 17 is large enough to extend beyond the angle of repose of the free owing solids in outlet lil and that, accordingly, the solids will not ow oi plate 17 when it is at rest but that they flow off that plate when the plate is reciprocating.

Mice

Means is provided in the lower -part of housing 15 for entraining the solids in the lower part of chamber 16 in an air stream and transporting them to a place of disposal. The means illustrated for this purpose includes a conduit Ztl which opens out of housing 15 near and below the free end of plate 17, a casing 21 Iwhich extends inwardly from the housing opposite :conduit Ztl and is open at each end with the inner iend 22 being disposed beneath plate `17, and a tube 23 disposed Within casing 21 and being -long enough to extend from the outer end of casing 21 to a point within conduit i251. A spider `24-, engaging the inner surface of the bottom wall of housing k15 and the upper inner surface of casing 21, receives and supports the tube 23 for sliding endwise movement. The outer end of tube 23 is bell-shaped as indicated at 30 and this portion of the tube serves to close the passage between casing 21 and tube 23 when the latter is in its innermost position as is shown in 'FIGURE 2. A pipe 25 is connected to housing 15 adjacent to outer ends of casing 21 and tube 23 and serves to conduct under pressure through the casing and tube. The conduit 20 is connected to a iixed tube by a ilexible tubular sleeve 20a.

Pipe 27 to which pipe 25 is connected by flexible connection 26 is provided with a shut off valve (not shown) to control the ow of air through pipe '25.

Means is provided for automatically controlling the discharge of solids into and out of hopper 1. This means includes valve means for automatically actuating gate 3 and tube 23 and position-sensing means for controlling that actuating means.

The means for actuating tube 23 includes a rod 31 which is connected to end 3i? of tube 23, has a sliding t in bearing 32 in pipe 25 and is connected to a piston (not shown) disposed within the cylinder 33 which is supported on a bracket 34- attached to the pipe 125. The ends of cylinder 33 are connected by ilexible `tubing 35 and 36 to a fourJway valve 37. The means for actuating gate 3 comprises iiexible tubing 38 and 39 connected to opposite ends of cylinder 4 and to four-way valve 37.

The position-sensing means which controls the operation of the pistons in cylinders d and 33 includes a frame which surrounds hopper 1, one side bar of which is shown at dil, and a pressure vessel 4S. At one end the frame is pivotally supported by fixed means 41. Diametrically opposite lugs d5 attached to hopper 1 rest on the bars 41 of the supporting frame so that the weight of the hopper, housing 15 and pipe 25 as well as the contents of the hopper are supported by that frame. At its end remote from support 51, the frame carries a depending rod 45 which is connected to, and passes through, the diaphragm portion 47 of the pressure vessel 48 and which carries at its lower end a valve 49 which serves to control the flow of air under pressure through tube 50 and into vessel 48. A bleed valve 51 serves to permit air under predetermined pressure to escape from vessel 48. The interior of the vessel 43 is connected by tubing 52 to four-way valve 37.

The four-way valve (FIG. 3) is of a conventional spring-loaded type, that is, a movable element or valve 55 in the valve housing 37 is moved by air pressure line 52 to connect tube Sil, leading from a source of air under pressure (not shown), with tubing 35 and 3d when there are solids in hopper 1 to be removed, and is moved by spring 56, when the air pressure falls below a predetermined minimum, to connect tube 5@ with tubing 39 and 36 when solids are to oe charged into hopper 1. Air trapped in the valve housing 37 at the ends of the valve 55 may escape through passages 57a and 57h.

When the air pressure in chamber 43 is above that predetermined minimum value and vibrator 1S is actuated, solids will be discharged from hopper 1 and will be transported into and through conduit 20 by air lowing through pipe 25, casing 2i and tube Z3. The pressure in chamber i8 is high enough to initiate and maintain iiow of air through casing 2.1 and tube 23 so long as there are solids in hopper il. When the hopper is emptied the spring in valve 37 takes charge with resultant closing of the passage through casing Zi and opening of gate 3. Since air will continue to iiow through pipe 25 and tube 23, such air flow will exert an aspirating action in the hopper and housing. Hence, solids iowing into hopper ll will be prevented from seeking outlets to the exterior of the hopper. Thus, the charging of the hopper will be clean and free from escaping dust.

Preferably, vibrator 18 is connected to a limit switch on gate 3 and is energized when the gate is fully closed but is deenergized when the gate is in any other position. This insures against back flow of fine solids around the gate and into the surrounding atmosphere.

It will be understood that the device disclosed by this application prevents solids from escaping into the atmosphere while being transferred into the hopper and that they are rapidly transported from the interior of the hopper to a place of disposal. it will also be understood that the disclosed device is substantially automatic in shifting from the solids handling action to the aspirating action and from the aspirating action to the dust handling action.

It will also be understood that the present invention may be embodied in apparatus which is quite inexpensive to manufacture and which is simple and automatic in operation.

Having thus described this invention in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same, and having set forth the best mode contemplated of carrying out this invention, I state that the subject matter which I regard as being my invention is particularly pointed out and distinctly claimed in what is claimed, it being understood that equivalents or modifications of, or substitutions for, parts of the above specifically described embodiment of the invention may be made without departing from the scope of the invention set forth in what is claimed.

What is claimed is:

1. A device for handling fine solids which comprises a hopper having an inlet in its upper portion and an outlet in its lower portion, a gate to open and close said inlet, a housing attached to the hopper and defining a chamber into which said outlet opens, means in the chamber below said outlet for feeding solids through said outlet and into said chamber, a conduit leading out of the chamber below said feeding means, and means to control the charging of solids into the hopper and their removal therefrom, said means including position-sensing means responsive to the weight of solids in the hopper, and a four-way valve controlled by said position-sensing means and adapted to control the movement of said gate and the removal of solids from the housing.

2. A device for handling fine solids which comprises a hopper having Aan inlet in its upper portion and an outlet in its lower portion, a gate to close said outlet, fluid pressure means to move said gate to open and closed position, a housing attached to the hopper and defining a chamber into which said outlet opens, means in the chamber below said outlet for feeding solids through said outlet and into the chamber, means energized by the closing of the gate for activating said feeding means, and means for transporting solids out of the chamber including a conduit leading out of the chamber below said feeding means, an open-ended movable tube to discharge air under pressure continuously into said chamber below said feeding means, a casing closable by said movable tube and yadapted when open to discharge air under pressure into said chamber, fluid pressure means to move said tube to open and close said casing, a four-way valve to control the flow of fluid under pressure to said gate moving means and to said tube moving means, and position-sensitive means actuated by limited vertical movemen-t of said hopper for actuating said four-way valve.

3. A device for handling fine solids which comprises:

(a) a hopper having an outlet in the lower portion,

(b) a housing attached to the hopper and defining a chamber into which said outlet opens,

(c) a solids feeder in the chamber below said outlet `and having a free end,

(d) a conduit leading out of said chamber and having au inlet end near and below the free end of said feeder,

(e) and means for selectively removing solids from said chamber and for reducing the air pressure in said hopper when solids are tto be charged thereinto,

(f) said Aremoving means including means to discharge an `air stream of la constant rate of flow and at a given velocity into said chamber beneath said feeder in solids transporting relation from the chamber through said conduit, `and said pressure reducing means including means to discharge an air stream at said constant rate `of liow but at increased velocity into said chamber near the inlet of said conduit,

(g) means including a four-way valve for selecting the desired 'air stream for the intended purpose and (lz) means controlled by the presence or absence of solids in Ithe hopper for actuating said valve.

4. A device for handling fine solids which comprises:

(a) a hopper having an outlet in the lower portion,

(b) a housing attached to the hopper and defining a chamber into which said outlet opens,

(c) a solids feeder in the chamber below said outlet and having a free end,

(d) a conduit leading out of said chamber and having an inlet end near and below the free end of said feeder,

(e) and means `for selectively removing solids from said chamber and for reducing the -air pressure in said hopper when solids are to be charged thereinto,

(f) said removing means including means to discharge an air stream of a constant rate of flow and at a given velocity into said chamber beneath said feeder in solids transporting relation from the chamber through said conduit, and said pressure reducing means including means to `discharge an air stream at said constant frate of flow but at increased velocity into said chamber near the inlet `of said conduit, and means including a four-way valve -for selecting the desired air stream for the intended purpose.

5. A device for handling fine solids which comprises:

(a) a hopper having an outlet in the lower portion,

(b) a housing attached to the hopper and defining a chamber into which said outlet opens,

(c) a solids feeder lin the chamber below said outlet and having a `free end,

(d) a conduit leading out of said chamber and having an inlet end near and below the free end of said feeder,

(e) and means for selectively removing solids from said chamber and for reducing the air pressure in said hopper when solids are to be charged thereinto,

(f) said removing means including means to discharge an air stream of a constant rate of flow 'and at a given velocity into said chamber beneath said feeder in solids transporting relation from the chamber through said conduit, and said pressure reducing means including means to discharge an air stream at said constant rate of iiow but at increased velocity into `said chamber near the inlet of said conduit.

6. A device for handling fine solids which comprises:

(fz) a hopper having an outlet in the lower portion,

(b) a housing `attached to the hopper and defining a chamber into which said outlet opens,

(c) a solids feeder in ythe chamber below said outlet and havling a free end,

(d) a conduit leading out of said chamber and having an inlet end near and below the free end of said feeder,

(e) means for selectively removing solids from said chamber including a fixed conduit having an open end below and near the free end of the feeder, and means to discharge an ailr stream of a const-ant rate of ow 'and at a given velocity through said ixed conduit,

(f) `and means -for reducing the air pressure in said hopper when solids are to be charged thereinto including a movable tube to close said fixed tube and having an open end beyond the free end of said feeder,

(g) a valve -for controlling the iiow of fluid under pressure through said fixed conduit and said tube,

and

(h) means actuated by limited Vertical movement of the hopper for actuating said valve.

References Cited in the tile of this patent UNITED STATES PATENTS 

1. A DEVICE FOR HANDLING FINE SOLIDS WHICH COMPRISES A HOPPER HAVING AN INLET IN ITS UPPER PORTION AND AN OUTLET IN ITS LOWER PORTION, A GATE TO OPEN AND CLOSE SAID INLET, A HOUSING ATTACHED TO THE HOPPER AND DEFINING A CHAMBER INTO WHICH SAID OUTLET OPENS, MEANS IN THE CHAMBER BELOW SAID OUTLET FOR FEEDING SOLIDS THROUGH SAID OUTLET AND INTO SAID CHAMBER, A CONDUIT LEADING OUT OF THE CHAMBER BELOW SAID FEEDING MEANS, AND MEANS TO CONTROL THE CHARGING OF SOLIDS INTO THE HOPPER AND THEIR REMOVAL THEREFROM, SAID MEANS INCLUDING POSITION-SENSING MEANS RESPONSIVE TO THE WEIGHT OF SOLIDS IN THE HOPPER, AND A FOUR-WAY VALVE CONTROLLED BY SAID POSITION-SENSING MEANS AND ADAPTED TO CONTROL THE MOVEMENT OF SAID GATE AND THE REMOVAL OF SOLIDS FROM THE HOUSING. 